The present invention relates to treatment of filter cigarettes, cigars, cigarillos and analogous rod-shaped smokers' articles which are provided with filter plugs or mouthpieces (hereinafter called filters for short) at one of their ends. More particularly, the invention relates to improvements in so-called tip turning of filter cigarettes or analogous smokers' articles (hereinafter called cigarettes for short). Tip turning involves inversion of a series of cigarettes in a filter tipping or an analogous machine wherein two parallel rows of cigarettes are transported in such a way that their filters are adjacent to one another.
Filter cigarettes are normally produced in a machine which places filter plugs of double unit length between pairs of filter cigarettes of unit length and thereupon drapes an adhesive-coated uniting band around each of the thus obtained groups in such a way that the uniting band surrounds the filter plug and the adjacent portions of the corresponding plain cigarettes. The resulting filter cigarettes of double unit length are severed midway across their filter plugs so that each filter cigarette of double unit length yields two filter cigarettes of unit length and the filters of cigarettes in one of the thus obtained rows are adjacent to the filters of cigarettes in the other row. The cigarettes of one row must be inverted or tip turned end-for-end in order to ensure that the filters of all cigarettes will face in the same direction during further processing, such as testing, segregation of defective cigarettes from satisfactory cigarettes, transport to storage, or transport into a packing machine.
Heretofore known tip turning apparatus for use in or with filter tipping machines normally include rotary turntables or sets of orbiting arms (see commonly owned U.S. Pat. No. 3,583,546 granted June 8, 1971 to Gerhard Koop) which accept the cigarettes of one row, turn them through 180 degrees, and place them between the non-inverted cigarettes of the other row. This results in the formation of a single third row wherein the orientation of all filters is the same, i.e., the filters of the single third row of cigarettes are disposed one behind the other and the tobacco-containing ends of all cigarettes are also disposed one behind the other. A drawback of heretofore known tip turning apparatus is that they subject the cigarettes to a relatively rough treatment which entails deformation and/or escape of tobacco particles at those ends which are remote from the filters. Furthermore, presently known tip turning apparatus are incapable of properly inverting cigarettes at the rate they are produced in a modern high-speed filter tipping machine. Still further, such conventional apparatus are actually likely to promote the escape of tobacco particles at those ends which are remote from the filters, primarily under the action of highly pronounced centrifugal forces which invariably develop during mass-production of filter cigarettes or the like in known filter tipping machines.